Replace `fides-js` direct calls to gvl.json with datamap data instead

[allisonking]

Is your feature request related to a specific problem?

There are 4 areas in fides-js where we still query the gvl.json directly:

• [x] Stacks
• [ ] Data categories
• [x] Privacy policy/Legitimate interest disclosure URLs
• [x] Cookie storage info
• [x] Data retention

Describe the solution you'd like

We need to route this data from the backend to the /privacy-experience endpoint so that the TCF overlay can render this.

Describe alternatives you've considered, if any

A description of any alternative solutions or features you've considered.

Additional context

Cookie storage info and privacy policy/legitimate interest disclosure urls can be done as part of https://github.com/ethyca/fides/issues/4255